SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '354b95f3941a461487ba22b313e4c909f29d79d041cd3799c96b519c2772fee7' 
  AND token = 'RW4bX94m8I8nC9BdVGpU72cCpQvhoDfdKj1bvlVqZvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}